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Character Classification (Windows Embedded CE 6.0)

1/5/2010

Character classification routines test a specified single-byte character or wide character for satisfaction of a condition. Generally these routines execute faster than tests you might write.

For example, the following code executes slower than a call to isalpha(c):

if ((c >= 'A') && (c <= 'Z')) || ((c >= 'a') && (c <= 'z'))
    return TRUE;

For detailed reference information about the CRT functions, see Alphabetical Function Reference (CRT).

The following table shows the conditions tested by character classification routines.

Routine Character Test Condition

__isascii, iswascii

Determines if character is ASCII.

_isctype, iswctype

Determines if character is a property specified by parameter.

isalnum, iswalnum

Determines if character is alphanumeric.

isalpha, iswalpha

Determines if character is alphabetic.

iscntrl, iswcntrl

Determines if character is a control.

isdigit, iswdigit

Determines if character is a decimal digit

isgraph, iswgraph

Determines if character is printable, other than space.

islower, iswlower

Determines if character is lowercase.

isprint, iswprint

Determines if character is printable.

ispunct, iswpunct

Determines if character is punctuation.

isspace, iswspace

Determines if character is white-space.

isupper, iswupper

Determines if character is uppercase.

isxdigit, iswxdigit

Determines if character is a hexadecimal digit.

See Also

Concepts

Run-Time Routines by Category

Other Resources

C/C++ Libraries for Windows Embedded CE
What's New in the C Run-Time Library